Introducing Baculo Virus Expression System (BVES) with a Strong IRES

Internal ribosome entry site (IRES) can be used to initiate translation of a second open reading frame (ORF) of an mRNA, providing the benefits of: 1) avoiding promoter competition in a dual promoter situation; 2) having controlled ratio of expression of two proteins; 3) placing a dominant selection pressure on the entire bicistronic mRNA and hence the maintenance of the transgene when a selection marker is placed as the second ORF.

IRES elements are located mainly in RNA viruses except certain mammalian and insect mRNA molecules. Only one DNA virus has so far been found to contain an IRES, the while spot syndrome virus (WSSV) of marine shrimp. This IRES, compared to a very few other choices known to function in insect cells such as the IRES from Rhopalosiphum padi virus (RhPV), has strong translation initiation activity (~98-99% in reference to cap-dependent initiation), insect cell specificity, and encompasses only 180 base pairs.

Allele Biotech, with its acquisition of Orbigen, is a major provider of BVES products and services with more than 10 years of experience. Allele’s featured New Products of the Week* this week are WSSV IRES containing baculovirus vectors, the sIRES (for Strong IRES from Shrimp virus) series plasmids. Currently one version is pOrb-MCS-sIRES-VSVG for pseudotyping baculoviruses (within the Emerald Baculovirus for Mammalian Expression series), with pOrb-mWasabi-sIRES-VSVG as a fluorescent protein control; the other is pOrb-MCS-sIRES-MCS for cloning a custom second cDNA. New versions in the future will include IRES driven mWasabi and other commonly used selection markers.

With a current research project for the National Cancer Institute (NCI) within the National Institutes of Health (NIH) involving development of modified BVES and mammalian protein expression and purification systems, Allele Biotech expects this product line to continue its expansion at a fast pace.

* Allele Biotech announces at least one new product every Wednesday through news release at AlleleNews or Allele Blog and social networks.

Tags: baculo, baculovirus, BVES, insect cells, IRES, NCI, NIH, Orbigen, ORF, protein expression, translation initiation

NIH Challenge Grant, First Released Program Based on the Stimulus Fund

At least 200 million dollars will be channeled through a new, one off mechanism called the Challenge Grants that were designed as jumpstart funds for 2-year projects. The review process will be quicker than normal; the start date will be by the end of September 09. Among the topics are 15 areas designated as Specific Challenge Topics by the NIH, and high priority topics that individual institute such as the NCI added by their choices. For instance, the Clinical Proteomic Technologies for Cancer program, of which Allele is a participant through a cancer marker antibody development project, is running several proteomic related topics that the Challenge Grants will fund.

Many new areas such as iPS, cancer stem cells, and resource development for stem cells are among the selected topics. All domestic institutions, academic or for-profit, are encouraged to apply. This announcement came a couple of weeks after the passage of the stimulus bill, from the NIH that does not yet have a permanent director or a HHS boss, one has to commend it as efficient work with focus. We are expecting that more programs are to come every week here on out until it becomes clear how all ARRA (The American Recovery and Reinvestment Act of 2009 or the stimulus fund) will be spent in the biomedical research field.

Tags: 200 million, Allele, antibody selection, ARRA, Challenge Grants, iPS, NCI, NIH, stem cells, stimulus package